# Revision History for language-nix
## 2.3.0
* `Language.Nix.Identifier` now exports `nixKeywords` which lists
keywords in Nix that are parseable as simple identifiers, but have
special meaning, like `assert` and `with`. Consequently, they can't
be used as (simple) identifiers in Nix code.
`quote`, `needsQuoting` and `Pretty` will take this list into account
and quote such identifiers. However, `HasParser` will _not_ reject them
even if they are unquoted.
* Resolved discrepancies between `Language.Nix.Identifier` and Nix w.r.t.
quoting and escaping:
- Fixed missing escaping of some Nix syntax elements, e.g. in the case of
`ident # "${foo}"`.
- Pretty printing `Identifier`s will no longer produce escape sequences
Haskell supports, but Nix doesn't.
- Parsing `Identifier`s won't interpret escape sequences that Nix wouldn't
understand.
* Added an hspec/QuickCheck based test suite.